The present invention generally relates to disk drives and more particularly to a frame structure of a disk drive that has a movable head or pickup.
In recent high-speed disk drives such as a magnetic disk drive called a hard disk drive, which carries information on a rigid magnetic disk, the speed of revolution of the disk is increasing for faster operation. Associated with this, the speed of movement of an actuator that carries a head is also increasing. In such high-speed disk drives, there is a keen demand for an improved design for efficient heat dissipation as well as for efficient suppression of vibration associated with such a high speed operation of the disk drive.
Typically, a magnetic disk drive has an actuator arm for carrying a magnetic head such that the magnetic head floats from the surface of the revolving magnetic disk by means of a thin air foil. By swinging the actuator arm back and forth about a swing axle, the magnetic head scans over the surface of the magnetic disk generally in a radial direction thereof.
FIG. 1 shows the construction of a typical conventional magnetic disk drive in a plan view.
Referring to FIG. 1, it will be noted that the magnetic disk drive includes an actuator 11 and a magnetic disk 12, wherein the actuator 11 carries an arm 13 that in turn supports a magnetic head 14 at a distal end thereof via a spring mechanism 13a. It should be noted that the arm 13 has a base part thereof held rotatably by a pivot mechanism 15 and swings back and forth about a swing axle of the pivot mechanism 15.
At the other end of the arm 13, there are formed support members 16a and 16b for holding a coil 17, and a pair of magnets 18a and 18b are disposed below the coil 17 with respective, opposite magnetic polarities. The magnets 18a and 18b are fixed on a chassis of the magnetic disk drive and form a voice coil motor 18 together with the coil 17.
The magnetic disk 12 is revolved by means of a spindle motor 12a, and the actuator 11 causes a scanning of the magnetic head 14 over the surface of the revolving magnetic disk 12 generally in a radial direction of the disk 12 in response to the energization of the coil 17. It should be noted that the actuator 11 is disposed on both sides of the magnetic disk 12, while the magnetic disk 12 is provided in plural numbers on a common drive axis such that the magnetic disks are revolved simultaneously and coaxially by the spindle motor 12a. The magnetic disks 12 and the actuators 11 are hermetically sealed by an enclosure or housing 19.
In recent magnetic disk drives, the speed of revolution of the spindle motor 12a is increasing for increased operational speed and reduced access time. Associated with such an increased speed of the magnetic disks, there is a demand for increased speed of movement of the actuators 11.
When the speed of movement of the actuator 11 is increased as such, there arises a problem of temperature rise in the hermetically sealed interior of the magnetic disk drive. Thus, there is provided a heat sink on the housing of the magnetic disk drive for dissipating heat. Further, the magnetic disk drive is mounted upon a frame for insulating vibration. Further, it should be noted that a plurality of such magnetic disk drives are assembled to form a disk module that provides a large storage capacity, several times as large as the storage capacity of the single magnetic disk drive.
FIGS. 2A and 2B show the construction of the frame structure used in conventional magnetic disk drives, wherein FIG. 2A shows a plane view while FIG. 2B shows a side view.
Referring to FIGS. 2A and 2B, it should be noted that a magnetic disk drive 21 is accommodated in a housing part 22, while the voice coil motor 18 that forms the essential part of the actuator mechanism 11 described previously, is covered by a another housing part 23. Further, FIG. 2A shows a heat sink structure 22a that includes a number of heat radiation fins for efficient dissipation of heat. The housing part 22 and the housing part 23 are connected with each other and form a hermetically sealed housing in which the rotary magnetic disks 12 and the actuators 11 are accommodated.
The magnetic disk drive 21 is mounted upon a U-shaped frame 24 that includes a pair of side plates 24a and 24b opposing each other, wherein the side plate 24a is provided with a support flange 25a as a part of the side plate 24a cut and bent inwardly. Similarly, the side plate 24b is provided with support flanges 25b and 25c as a part of the side plate 24b cut and bent inwardly. As will be described in detail below with reference to FIGS. 3A and 3B, the support flanges 25a and 25b carry respective vibration insulators 26a and 26b and support the housing part 22 of the magnetic disk drive via the vibration insulators 26a and 26b. Similarly, the support flange 25c carries a vibration insulator 26c and support the housing part 23 of the magnetic disk drive via the vibration insulator 26c. Thereby, the housing part 22 is fixed upon the support flanges 25a and 25b by way of screws 27a and 27b, while the housing part 23 is fixed upon the support flange 25c by way of a screw 27c and a mount bracket 28 attached to the housing part 23.
FIGS. 3A and 3B show the support flanges 25b and 25c in detail.
Referring to FIG. 3A, it will be noted that the vibration insulator is formed of a rubber sleeve having upper and lower rubber flanges 26b.sub.1 and 26b.sub.2 disposed at both sides of the support flange 25b, and the screw 27b is threaded into the support flange 25b through the sleeve of the vibration insulator 26b for fixing the housing 22 of the magnetic disk drive. Similarly, the housing 22 is mounted upon the support flange 25c by means of the screw 27c and the bracket 28, such that a rubber member acting as the vibration insulator 26c is interposed between the bracket 28 and the support point 25c.
The magnetic disk drive having such a conventional construction dissipates the heat generated inside the housing 22 by way of the heat radiation fins 22a on the housing 22. Further, the vibration caused by the spindle motor 12 or the voice coil motor 18 is suppressed by way of the vibration insulators 26a-26c. It should be noted that a plurality of magnetic disk drives each having a construction of the magnetic disk drive 21 are mounted upon corresponding frames 24, and such a plurality of the magnetic disk drives form the magnetic disk module mentioned previously.
In the recent high-speed disk drives, however, such a conventional construction of the housing 22 for heat dissipation is not sufficient for suppressing the temperature rise inside the housing 22. As a result of excessive temperature rise, conventional high-speed disk drives have suffered from the problems such as increased off-track, damaging or deterioration of mechanical parts such as bearings or flexible printed circuit boards, as well as deterioration in performance of the integrated circuits provided inside the housing 22. When forced-air-cooling is employed for eliminating this problem, on the other hand, one encounters a problem of excessive cost of the device. Thus, the problems pertinent to such conventional magnetic disk drives urge the development of a further improved design of vibration insulation that is also effective for efficient heat dissipation.